Folding walls are well-known as wave or folding walls. They are usually used as part of a transition between two articulated vehicle units and, as such, surround the transition bridge tunnel-like. Folding walls are also known in passenger boarding bridges or gangways.
With wave or folding walls, the individual folds or waves consist of sheets of material, with the each wave or fold sheet being connected to an adjacent wave or fold sheet in order to form the wave or folding wall, in particular by means of a folding wall frame, as is known from the prior art.
Especially with a folding wall, the design is such that the folding wall frames are provided only on the outer side of the folding wall to secure the transition between two folds.
The sheet of such a wall comprises at least one reinforcement element, for example, in the form of a fabric, a knitted fabric, or a scrim, with this reinforcement element usually being coated on both sides. A wide variety of rubber or rubber compounds are available for the coating, including elastomers in the form of vulcanized silicone rubber or organic rubbers, such as CSM (chloro-sulfonated polyethylene). The advantage of using an elastomer based on a silicone rubber for coating the reinforcing elements for the manufacture of a folding wall, for example in rail transport, is a high level of flame resistance of silicone, good colorability, and the increased temperature flexibility. A disadvantage of the use of silicone rubbers is the high price.
In addition, there are also folding walls made of a fabric coated with an organic elastomer, such as a CSM, with organic elastomers being cheaper than silicone elastomers. A fabric coated, for example, with a CSM elastomer is not quite as flexible as a fabric coated with a silicone elastomer, and, in addition, it cannot be manufactured in all colors. So, for example, it is not possible to produce a coating with a white CSM. This is so, because such a CSM is already not white in its basic substance and, to make matters worse, it does change its color in the sun, albeit slowly. In terms of flame resistance, specific measures must be taken to make such a fabric coated with CSM flame resistant.
In contrast, a fabric coated with vulcanized silicone rubber can not only be made flame-resistant, but is also stable at higher temperatures.
In this context it should be noted that the flame resistance and the color stability on the outside of a folding wall is of relevance. This is so, because this side of the folding wall is exposed to the weather, and—in addition—it has turned out to also be an advantage if the color can be precisely matched to the color of, for example, the main vehicle body.